Residents of a country where they are not a citizen, like me (American living in Germany). A year from now, I might decide to visit my home country, and even be

Residents of a country where they are not a citizen, like me (American living in Germany). A year from now, I might decide to visit my home country, and even be allowed back in, and if I stood in the customs line in Amsterdam near a Frenchman who hung out with someone in Montreal who turned up positive, it would be in everyone's interest for me to know I was exposed. Even traveling between Munich and Nuremberg, a one hour trip, I might be on a train near an Austrian who saw no reason to leave Munich during all this heading up to Berlin to finish a consulting contract, but a week ago had been in a meeting with a German who turned up positive. Our Austrian consultant would have been allowed to stay this past "shelter-in-place" month if she had a lease on an apartment and had registered it as her primary residence - no residence permit required, as she's an EU citizen. Again, it would be in everyone's interest for the three of us (and everyone we had much time around) to know about when the exposure took place and that we might need to self-quarantine/be tested.